Electrical plug-in connectors used between igniter modules and electronic control units in motor vehicles have to meet extremely high safety requirements with regard to plug-in safety and contact safety. Both plug-in safety and contact safety have to be ensured for a long period of time and under partly extreme conditions such as vibrations and severe temperature fluctuations.
At the same time, such plug-in connectors have to be ever cheaper, lighter, smaller, and easier to assemble. An intuitive operation of the unlocking should be provided when being unlocked, preferably without the need for tools.
Additional requirements include low insertion force with distinct acoustic and/or tactile feedback during plugging in, an indication of the condition of the plug, and a geometric shape that provides the maximum safety against external interference.